“Immediately he made the disciples get into the boat and go before him to the other side, while he dismissed the crowds. And after he had dismissed the crowds, he went up on the mountain by himself to pray. When evening came, he was there alone, but the boat by this time was a long way from the land, beaten by the waves, for the wind was against them. And in the fourth watch of the night he came to them, walking on the sea. But when the disciples saw him walking on the sea, they were terrified, and said, “It is a ghost!” and they cried out in fear. But immediately Jesus spoke to them, saying, ‘Take heart; it is I. Do not be afraid.’”
When Jesus had gone to pray it was just after sunset. As the night progressed, a storm descended on the disciples in the boat on the Sea of Galilee. They made little headway as the boat was tossed about by the waves and the wind blowing from the direction they wanted to go. Ancient people understood the terrifying nature of such wild and raging waters. They believed that the seas were the realm of chaos, danger, and death. They were unpredictable. They could not be controlled or tamed. And we can appreciate this to some extent. We have seen the devastation resulting from raging storm surge of hurricanes and maybe we experienced it ten years ago with Sandy. And you may recall the great tsunami of December 2004 that took the lives of over 200000 people in South Asia. Even with all our modern technology we cannot control the seas or the storms. We can predict, prepare, react, but not control or prevent such chaos from occurring.
Jesus came to the disciples on the sea during the 4th watch, 3:00 to 6:00 in the morning. So the disciples had been battling the storm for several hours, rowing against wind and waves. After all their exertion, they were wet, weary, frustrated, frightened, and far from shore.
So when they saw Jesus walking toward them on the surface of the water, they did not recognize Him. They were terrified, and cried out in fear “It is a ghost!” thinking it was the specter of death, come to drag them down to a watery grave. In light of what Jesus had done for them in the past, they need not have been afraid. They should have known Jesus would save them. But He was not there with them.
Jesus answered them “take courage it is I.” The words Jesus actually spoke as written by Matthew were I am. I am. This is the name of the Lord God, in the Old Testament, Yahweh, I am who am. Jesus used this phrase many times. I am the way the truth and the life. I am the bread of life. Before Abraham was I am. Jesus is saying He is God. He is master of the wind and waves and He shows us. He enables Peter to walk on the sea, however briefly, rescues him from drowning when his faith wavers, and immediately calms the storm when they get into the boat.